Integrated circuits, also referred to as "chips", are widely used in consumer and commercial electronic products. As is well known to those having skill in the art, an integrated circuit generally includes a substrate such as a semiconductor substrate and an array of bonding pads on the substrate. The bonding pads provide an electrical connection from outside the integrated circuit to microelectronic circuits in the integrated circuit.
In the design of high performance integrated circuits, it is generally desirable to provide a low electrical resistance in the bonding pads. Unfortunately, as the integration density of integrated circuits continues to increase, more bonding pads may be needed in the integrated circuit, so that the area of each bonding pad may be lowered. Unfortunately, as the bonding pad becomes smaller, the resistance thereof may increase.
Moreover, as the integrated circuit device becomes more highly integrated, a step between the bonding pad and an insulating layer around the bonding pad may be produced. Reaction residue that is generated during a process of forming a contact hole on the insulating layer in order to expose the bonding pad, may become stacked at the edge of the step. The reaction residue may increase the contact resistance of the bonding pad.